Nora Sanderson had been adopted about twenty years ago-- and then came a telephone call from ""Daddy"" who had memories and a blood-relative feeling that came up as tender blackmail. Eleanor Howell was a social worker, who had stayed with the same agency for a long time-- a ""safe"" woman who began to lead a dangerous life. Through it all is the track of the cat, from the surface paw print to the psychological scar. The Lockridges are past masters of the mystery-entertainment and five non-fiction titles are evidence of their cat concerns. An excellent combination.